1619 Beak Trimming Methods -Review - P. C. Glatz* Pig and Poultry Production Institute, South Australian Research and Development Institute Roseworthy, South Australia, 5371, Australia ABSTRACT : A review was undertaken to obtain information on the range of beak-trimming methods available or under development. Beak-trimming of commercial layer replacement pullets is a common yet critical management tool that can affect the performance for the life of the flock. The most obvious advantage of beak-trimming is a reduction in cannibalism although the extent of the reduction in cannibalism depends on the strain, season, and type of housing, flock health and other factors. Beak-trimming also improves feed conversion by reducing food wastage. A further advantage of beak-trimming is a reduction in the chronic stress associated with dominance interactions in the flock. Beak-trimming of birds at 7-10 days is favoured by Industry but research over last 10 years has shown that beak-trimming at day-old causes the least stress on birds and efforts are needed to encourage Industry to adopt the practice of beak-trimming birds at day-old. Proper beak-trimming can result in greatly improved layer performance but improper beak-trimming can ruin an other wise good flock of hens. Re-trimming is practiced in most flocks, although there are some flocks that only need one trimming. Given the continuing welfare scrutiny of using a hot blade to cut the beak, attempts have been made to develop more welfare friendly methods of beak-trimming. Despite the developments in design of hot blade beak-trimmers the process has remained largely unchanged. That is, a red-hot blade cuts and cauterises the beak. The variables in the process are blade temperature, cauterisation time, operator ability, severity of trimming, age of trimming, strain of bird and beak length. This method of beak-trimming is still overwhelmingly favoured in industry and there appears to be no other alternative procedures that are more effective. Sharp secateurs have been used trim the upper beak of both layers and turkeys. Bleeding from the upper mandible ceases shortly after the operation, and despite the regrowth of the beak a reduction of cannibalism has been reported. Very few differences have been noted between behaviour and production of the hot bJade and cold blade cut chickens. This method has not been used on a large scale in Industry. There are anecdotal reports of cannibalism outbreaks in birds with regrown beaks. A robotic beak-trimming machine was developed in France, which permitted simultaneous, automated beak-trimming and vaccination of day-old chicks of up to 4,500 chickens per hour. Use of the machine was not successful because if the chicks were not loaded correctly they could drop off the line, receive excessive beak-trimming or very light trimming. Robotic beak-trimming was not effective if there was a variation in the weight or size of chickens. Capsaicin can ca니se degeneration of sensory nerves in mammals and decreases the rate of beak regrowth by its action on the sensory nerves. Capsaicin is a cheap, non-toxic substance that can be readily applied at the time of less severe beak-trimming. It suffers the disadvantage of causing an extreme burning sensation in operators who come in contact with the substance during its application to the bird. Methods of applying the substance to minimise the risk to operators of coming in contact with capsaicin need to be explored. A method was reported which cuts the beaks with a laser beam in day-old chickens. No details were provided on the type of laser used, or the severity of beak-trimming, but by 16 weeks the beaks of laser trimmed birds resembled the untrimmed beaks, but without the bill tip. Feather pecking and cannibalism during the laying period were highest among the laser trimmed hens. Currently laser machines are available that are transportable and research to investigate the effectiveness of beak-trimming using ablasive and coagulative lasers used in human medicine should be explored. Liquid nitrogen was used to declaw emu toes but was not effective. There was regrowth of the claws and the time and cost involved in the procedure limit the potential of using this process to beak-trim birds. (Asian-Aus. J. Anim. Sci. 2000. VoL 13, No. 11 : 1619-1637) Key Words : Cannibalism, Poultry Welfare, Beak Trimming INTRODUCTION upper and lower beak using an electrically heated blade. Without a correct beak-trimming program, the Beak-trimming is performed early in the life of egg producer risks heavy losses of chickens and commercial hens to decrease injuries caused by the pullets from cannibalism and in the laying stage from behavioural vices of cannibalism, bullying and feather protrusion and vent pick outs. In many cases these and vent pecking and to avoid feed wastage. losses represent the major part of mortality not caused Beak-trimming is known to help flocks with a hysteria by disease. If birds are not trimmed, mortality of up problem. For the majority of birds beak-trimmed in to 25-30% of the flock will occur and can be the world today, it involves the partial removal of the financially as disastrous as a disease outbreak. It .is possible to rear pullets without beak-trimming if there * Address reprint request to P. C. Glatz. Tel: +61-8-830377 is effective light control. However once an outbreak 86, Fax: +61-8-83037977, E-mail: [email protected]. has occurred it is difficult to control cannibalism. 1620 P. C. GLATZ Under some conditions it might be possible to manage by disease. If birds are not trimmed, mortality of up laying hens without beak-trimming, but for most to 25-30% of the flock will occur and can be producers, the risk of such a policy are too high. Bell financially as disastrous as a disease outbreak (Bolla, (1996) reports that care must be taken when 1977, 1990; Glatz, 1990). considering the "no trim" form of management. He states ''elimination of beak-trimming may seem to be CANN 旧 A 니SM an attractive goal but it must be done with caution and careful consideration of all the consequences^. Outbreaks of cannibalism are clearly recognisable. A concern expressed by welfare groups is that The evidence of blood stained birds, broken skin, raw beak-trimming is "a discredited mutilation and farmers wounds and injured vents which are occasionally who still practice it should be brought into line by mistaken for prolapse are all clear indicators of law. It is a last ditch measure to avoid the cannibalism. Many causes of cannibalism have been consequences of bad management. If stocking densities suggested. Often outbreaks occur in one pen while are too high, the diet not balanced, or if lighting is at similar environmental conditions or feeding practices in fault, stress-aggression occurs. To overcome it the other pens on the same farm do not cause any beak is burned off cutting through a bed of highly difficulty. Savory (1995) and Savory and Mann (1997) sensitive nerve tissue, similar to the quick of the report that cannibalism develops either as a result of human finger nail". On the other hand the prevention misdirected ground pecking or is associated with the of cannibalism is seen as a positive contribution to dust bathing behaviour. If a bird has died due to a animal welfare as the pain and suffering resulting pick-out in a cage, other birds in the cage may be from cannibalism, may be much greater resulting in next, usually caused by an individual bird engaging in the death of the bird. Many producers believe that on vent pecking. In this situation all birds should be balance the practice of beak-trimming is to be taken out of the cage and oviduct everted to examine favoured, provided that the operation is performed the mucosa inside the cloaca and the lower part of properly. Decision about beak-trimming includes the the reproductive tract. It is likely that there will be age to trim, amount of beak to remove, temperature of damage observed, caused by the pecking bird. One or the blade and length of time to cauterise the beak. more wounds, produced by the pecking will be seen These factors coupled with differences in beak growth while the other hens were laying eggs on the previous characteristics have the potential to create an endless day. The damage affects the muscular activity of these number of combinations many of which may be tissues and produces a blow-out a few days later. harmful to the individual bird. The beak-trimming Forceful pecking is directed at bare skin leading to method needs to be tailored to strain. One method haemorrhage (Savory, 1995), attracting other birds to may work with one strain but maybe quite inadequate join in the pecking. Death of the pecked bird usually for another strain. The problem facing producers is results. Vent pecking appears unrelated to the tissue that they are sometimes unsure of the age to trim pecking although shares some of its features (Savory, chickens and the method to use. The following review 1995). It may be related to hormonal changes. Picking was undertaken to provide information on the effects of the vent region or region of the abdomen several and best practice for trimming and re-trimming and inches below the vent is the severest form of procedures required to reduce the need for re­ cannibalism. Predisposing conditions are prolapses or trimming. tearing of the tissues by passage of an abnormally large egg. Alternatively pecking may be directed at the WHY ARE BIRDS BEAK-TRIMMED? small downy feathers below the cloaca.